diff --git a/examples/cpp/snap7.h b/examples/cpp/snap7.h
index 23cf5fd..30f4783 100644
--- a/examples/cpp/snap7.h
+++ b/examples/cpp/snap7.h
@@ -596,7 +596,7 @@ const longword evcDirectory           = 0x01000000;
 const longword evcSecurity            = 0x02000000;
 const longword evcControl             = 0x04000000;
 const longword evcGroupProgrammer     = 0x08000000;
-const longword evcCyclicData          = 0x10000000;
+const longword evcGroupCyclicData     = 0x10000000;
 const longword evcReserved_20000000   = 0x20000000; // actually unused
 const longword evcReserved_40000000   = 0x40000000; // actually unused
 const longword evcReserved_80000000   = 0x80000000; // actually unused
@@ -620,6 +620,7 @@ const word evsGPBlink                 = 0x0002;
 const word evsGPRequestDiag           = 0x0003;
 const word evsGPReadDiag              = 0x0004;
 const word evsGPRemoveDiag            = 0x0005;
+const word evsGCRequestData           = 0x0001;
 // Event Params : functions group
 const word grProgrammer               = 0x0041;
 const word grCyclicData               = 0x0042;
diff --git a/src/core/s7_server.cpp b/src/core/s7_server.cpp
index 53c36bf..2cfe663 100644
--- a/src/core/s7_server.cpp
+++ b/src/core/s7_server.cpp
@@ -1672,7 +1672,7 @@ bool TS7Worker::PerformGroupCyclicData()
     // Check request and send appropriate answer
 
     if (RequestParams->SubFun == SFun_Profinet) {
-
+        evs = evsGCRequestData;
         AnswerData->ReturnCode      = ReturnCode_Success;
         // Set transport size of Data to OCTET:
         AnswerData->TransportSize   = TS_ResOctet;
@@ -1693,8 +1693,7 @@ bool TS7Worker::PerformGroupCyclicData()
         0xb6, 0x00, 0x00, 0x00, 0x00 };
 
         // Fill Answer with Response Data
-        int i;
-        for (i = 0; i < sizeof(ResponseData); i++) {
+        for (size_t i = 0; i < sizeof(ResponseData); i++) {
             AnswerData->Data[i] = ResponseData[i];
         }
 
@@ -1716,7 +1715,7 @@ bool TS7Worker::PerformGroupCyclicData()
     }
 
     // TODO sent correct events
-    DoEvent(evcCyclicData,evrNotImplemented,grCyclicData,0,0,0);
+    DoEvent(evcGroupCyclicData,evrNoError,0,0,0,0);
     return true;
 }
 //==============================================================================
diff --git a/src/core/s7_text.cpp b/src/core/s7_text.cpp
index 0064c13..3f8927e 100644
--- a/src/core/s7_text.cpp
+++ b/src/core/s7_text.cpp
@@ -523,6 +523,15 @@ static BaseString GroupProgrammerText(TSrvEvent &Event)
     };
 }
 //---------------------------------------------------------------------------
+static BaseString GroupCyclicDataText(TSrvEvent &Event)
+{
+    switch (Event.EvtParam1)
+    {
+        case evsGCRequestData : return "Group Cyclic Data: Request Cyclic Data";
+        default               : return "Group Cyclic Data: Unknown Subfunction";
+    };
+}
+//---------------------------------------------------------------------------
 BaseString EvtSrvText(TSrvEvent &Event)
 {
     BaseString S;
@@ -543,6 +552,7 @@ BaseString EvtSrvText(TSrvEvent &Event)
             case evcDirectory      : S=BlockInfoText(Event);break;
             case evcSecurity       : S=SecurityText(Event);break;
             case evcGroupProgrammer: S=GroupProgrammerText(Event);break;
+            case evcGroupCyclicData: S=GroupCyclicDataText(Event);break;
             default:               S="Unknown event ("+IntToString(Event.EvtCode)+")";break;
         }
         return SenderText(Event)+S;
diff --git a/src/core/s7_types.h b/src/core/s7_types.h
index 11f4830..69a875c 100644
--- a/src/core/s7_types.h
+++ b/src/core/s7_types.h
@@ -106,7 +106,7 @@ const longword evcDirectory           = 0x01000000;
 const longword evcSecurity            = 0x02000000;
 const longword evcControl             = 0x04000000;
 const longword evcGroupProgrammer     = 0x08000000;
-const longword evcCyclicData          = 0x10000000;
+const longword evcGroupCyclicData     = 0x10000000;
 const longword evcReserved_20000000   = 0x20000000;
 const longword evcReserved_40000000   = 0x40000000;
 const longword evcReserved_80000000   = 0x80000000;
@@ -127,6 +127,7 @@ const word evsGPBlink                 = 0x0002;
 const word evsGPRequestDiag           = 0x0003;
 const word evsGPReadDiag              = 0x0004;
 const word evsGPRemoveDiag            = 0x0005;
+const word evsGCRequestData           = 0x0001;
 // Event Result
 const word evrNoError                 = 0;
 const word evrFragmentRejected        = 0x0001;